不同形貌纳米二硫化钼制备研究进展

纳米二硫化钼由于具有层状结构、大的比表面积和稳定的伏安特性,在摩擦、催化、电极材料等领域有着广泛的应用前景。对不同形貌纳米二硫化钼的制备研究现状进行总结归纳,比较分析富勒烯、球状、管状等纳米结构二硫化钼的制备方法和形成机理,并展望纳米二硫化钼的研究发展趋势。     

生物质碳负载铁-钴磁性复合材料的合成及在染料废水处理中的应用

利用固相热还原法一步合成了生物质碳负载的铁-钴(Fe-Co/C)磁性吸附材料,并考察了材料对亚甲基蓝(MB)的磁性吸附分离性能。研究结果表明:制得的Fe-Co/C为松散的片状结构,具有较大的比表面积,Fe-Co/C对MB吸附1h和6h的吸附率分别达到97%和99.0%,具有较好的吸附性能。     

氯化镨气溶胶的高温热解机制研究

以PrCl_3气溶胶为前驱体,在微纳米尺度研究了PrCl_3在空气氛围中的高温热解行为,分别用X射线衍射(XRD)和场发射扫描电镜(FESEM)对热解产物的物相组成和微观形貌进行表征分析。一般地,通过煅烧Pr_2(C_2O_4)_3或Pr_2(CO_3)_3得到的氧化镨是非化学计量比形式的Pr_6O_(11),然而PrCl_3气溶胶在空气氛围中的热解产物中生成了具有化学计量比形式的二氧化镨(PrO_2)。PrCl_3气溶胶热解产物的XRD分析结果表明:在600℃时的热解产物为Pr(OH)_2Cl和少量PrOCl,700～1000℃时为Pr(OH)_2Cl,PrOCl和PrO_2,1100℃时为PrO_2和少量的Pr(OH)_2Cl物相,随着热解温度的升高热解产物中PrO_2的含量逐渐增多。以热力学摩尔最小吉布斯自由能变为判据分析了PrCl_3热解生成PrO_2时的热力学趋势及其可能的热解化学反应途径;根据产物的形貌特征及热解过程的特点,探讨了导致PrCl_3气溶胶热解生成PrO_2的潜在原因;采用热重分析-示差扫描量热(TG-DSC)研究了PrO_2在空气氛围中的热稳定性,结合PrO_2静态焙烧产物的物相组成明晰了在300～1100℃范围内PrO_2的热解转化方向,通过热力学计算分析了不同形式氧化镨相互转变的化学反应途径。是对氯化镨热解机制及氧化镨性质认识的重要补充,并为研究其他金属氯化物的热解机制提供了一种新方法与思路。     

Effect of loaded organic phase containing mixtures of silicon and aluminum, single iron on extraction of lanthanum in saponification P507-HCl system

Emulsification troubled normal extraction process of rare earths due to the existence of non-rare earth impurities,especially Si,Al and Fe.Against this background,the effect of emulsification caused by Si,Al and Fe on the La extraction with saponification P507(2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester) in chloride medium was systematically investigated.A series of experiments were carried out to study the relationship of the extraction capacity of La and the concentration of impurities.ZPM-203 polarizing microscope was applied to investigate the morphology of emulsification,and the cation exchange extraction mechanism of Fe and Al as well as La was clarified by IR spectra.The results showed that a low concentration of Si in organic phase would aggravate the emulsification with Al,and the formation of ME(micro emulsion) and club-shaped polymer would result in emulsification in the extraction of mixtures of Si and Al,single Fe,respectively.Furthermore,the accumulation of impurity such as Si,Al and Fe in the organic phase would severely reduce the extraction capacity of La simultaneously.     

固相一步合成碳负载磁性吸附材料及其在染料废水中的应用

以农业生物质甘蔗渣为碳源、氯化钴和氯化镍为前驱体,通过固相一步热还原法制备了Co-Ni/C磁性吸附材料,并将之用于对亚甲基蓝的吸附和磁性分离。利用生物质碳和磁性纳米粒子的协同作用,室温条件下在6 h内该磁性吸附剂对染料的吸附率达99%。这种廉价、高效的吸附剂有望实现大规模制备,并在将来的水污染处理领域中发挥重要的作用。